Today email has become the top activity on smartphones, which is ahead of browsing popular social media sites. Therefore, if you are a marketer, you have a great opportunity to contact individuals with your Email marketing messages through the devices they are using most frequently.

1. Reflect on responsive email design: Creating responsive, designed emails has become quite important today as the majority of people today uses smartphones and use email as their major "app." Although creating a responsive, designed email template is not an easy thing to do, still you can take the help of your email service provider or marketing automation vendor to create a responsive designed email template.

2. Call to action button must be big and noticeable: It is always advisable to make your call to action button obvious, big and easy to click. Because subscribers will not search for your call to action button, therefore it should be easily visible.

3. Add Images: Most email clients have images enabled by default on their smartphones. So, you must think carefully about what imagery you are using in your marketing campaign. Images matter a lot and play a very important role in a marketing campaign. Therefore, instead of using any random image use images that are linked to the content and are eye catching. Moreover, by just seeing the image your audience can find out what message you are trying to convey.

4. The subject line should be proper: A compelling and creative subject line can make your audience go through your email, otherwise people generally tend to delete or ignore messages that do not have a good subject line. Your subject line should be direct and descriptive in- order to make your audience go through your mail.

Resources:
http://bluemailmedia.com/

http://www.entrepreneur.com/article/229618